Structural Disorder of AlMg‐Oxide Phase Supporting Cu/ZnO Catalyst Improves Efficiency and Selectivity for CO2 Hydrogenation to Methanol

• Published in: ChemCatChem 2023-07, Vol.15 (13), p.n/a
• Main Authors: Mavrič, Andraž, Žerjav, Gregor, Belec, Blaž, Roškarič, Matevž, Finšgar, Matjaž, Pintar, Albin, Valant, Matjaž
• Format: Article
• Language: English
• Subjects: Carbon dioxide; carbon dioxide hydrogenation; Catalysts; Catalytic activity; Copper; Heat treatment; heterogenous catalysis; Hydrogenation; Methanol; reducibility; Zinc oxide
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.202300428

The performance of the Cu/ZnO catalyst system with the AlMg‐oxide phase is studied for CO2 hydrogenation to methanol. The catalyst is prepared by thermal treatment of the hydrotalcite phase containing intimately mixed metal cations in the hydroxide form. CuO in the presence of ZnO and disordered AlMg‐oxide phase gets easily reduced to Cu during the hydrogenation reaction. Its catalytic activity at relatively low Cu metal content (∼14 at.%) remains stable during 100 hours on stream at 260 °C with constant space‐time yield for methanol (∼1.8 gMeOH gcat−1 h−1) and high methanol selectivity (>85 %) The improved performance is attributed to the neutralization of surface acidity, increased number of weak basic sites in the disordered phase, and lower tendency for coke formation. The performance of the Cu/ZnO catalyst system for CO2 hydrogenation to methanol is improved by using disordered AlMg‐oxide support. The disorder in the mixed metal oxide is characterized by lower surface acidity, increased number of weak basic sites and lower tendency for coke formation. The interactions of Cu with a disordered phase increase Cu reducibility and improve catalyst stability.